err.no Git - linux-2.6/blob - drivers/s390/char/sclp_info.c

   1 /*
   2  *  drivers/s390/char/sclp_info.c
   3  *
   4  *    Copyright IBM Corp. 2007
   5  *    Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
   6  */
   7
   8 #include <linux/init.h>
   9 #include <linux/errno.h>
  10 #include <linux/string.h>
  11 #include <asm/sclp.h>
  12 #include "sclp.h"
  13
  14 struct sclp_readinfo_sccb {
  15         struct  sccb_header header;     /* 0-7 */
  16         u16     rnmax;                  /* 8-9 */
  17         u8      rnsize;                 /* 10 */
  18         u8      _reserved0[24 - 11];    /* 11-23 */
  19         u8      loadparm[8];            /* 24-31 */
  20         u8      _reserved1[48 - 32];    /* 32-47 */
  21         u64     facilities;             /* 48-55 */
  22         u8      _reserved2[91 - 56];    /* 56-90 */
  23         u8      flags;                  /* 91 */
  24         u8      _reserved3[100 - 92];   /* 92-99 */
  25         u32     rnsize2;                /* 100-103 */
  26         u64     rnmax2;                 /* 104-111 */
  27         u8      _reserved4[4096 - 112]; /* 112-4095 */
  28 } __attribute__((packed, aligned(4096)));
  29
  30 static struct sclp_readinfo_sccb __initdata early_readinfo_sccb;
  31 static int __initdata early_readinfo_sccb_valid;
  32
  33 void __init sclp_readinfo_early(void)
  34 {
  35         int ret;
  36         int i;
  37         struct sclp_readinfo_sccb *sccb;
  38         sclp_cmdw_t commands[] = {SCLP_CMDW_READ_SCP_INFO_FORCED,
  39                                   SCLP_CMDW_READ_SCP_INFO};
  40
  41         /* Enable service signal subclass mask. */
  42         __ctl_set_bit(0, 9);
  43         sccb = &early_readinfo_sccb;
  44         for (i = 0; i < ARRAY_SIZE(commands); i++) {
  45                 do {
  46                         memset(sccb, 0, sizeof(*sccb));
  47                         sccb->header.length = sizeof(*sccb);
  48                         sccb->header.control_mask[2] = 0x80;
  49                         ret = sclp_service_call(commands[i], sccb);
  50                 } while (ret == -EBUSY);
  51
  52                 if (ret)
  53                         break;
  54                 __load_psw_mask(PSW_BASE_BITS | PSW_MASK_EXT |
  55                                 PSW_MASK_WAIT | PSW_DEFAULT_KEY);
  56                 local_irq_disable();
  57                 /*
  58                  * Contents of the sccb might have changed
  59                  * therefore a barrier is needed.
  60                  */
  61                 barrier();
  62                 if (sccb->header.response_code == 0x10) {
  63                         early_readinfo_sccb_valid = 1;
  64                         break;
  65                 }
  66                 if (sccb->header.response_code != 0x1f0)
  67                         break;
  68         }
  69         /* Disable service signal subclass mask again. */
  70         __ctl_clear_bit(0, 9);
  71 }
  72
  73 unsigned long long __init sclp_memory_detect(void)
  74 {
  75         unsigned long long memsize;
  76         struct sclp_readinfo_sccb *sccb;
  77
  78         if (!early_readinfo_sccb_valid)
  79                 return 0;
  80         sccb = &early_readinfo_sccb;
  81         if (sccb->rnsize)
  82                 memsize = sccb->rnsize << 20;
  83         else
  84                 memsize = sccb->rnsize2 << 20;
  85         if (sccb->rnmax)
  86                 memsize *= sccb->rnmax;
  87         else
  88                 memsize *= sccb->rnmax2;
  89         return memsize;
  90 }
  91
  92 /*
  93  * This function will be called after sclp_memory_detect(), which gets called
  94  * early from early.c code. Therefore the sccb should have valid contents.
  95  */
  96 void __init sclp_get_ipl_info(struct sclp_ipl_info *info)
  97 {
  98         struct sclp_readinfo_sccb *sccb;
  99
 100         if (!early_readinfo_sccb_valid)
 101                 return;
 102         sccb = &early_readinfo_sccb;
 103         info->is_valid = 1;
 104         if (sccb->flags & 0x2)
 105                 info->has_dump = 1;
 106         memcpy(&info->loadparm, &sccb->loadparm, LOADPARM_LEN);
 107 }